Lifting-skid for sawmill feed mechanism.



No. 887,075. PATENTED MAY 12, 1908.'

H. G. DITTBENNER. LIFTING SKID FOR SAWMILL FEED MEGHANISM.

.APPLICATION FILED AUG. 22. 1907.

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Application filed August 22, 1907.

.To all whom it may concern.'

Be it known that lf, HERMANN G. DITT- BENNER, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in LiftingSkids for Sawmill Feed Mechanism, and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to saw mills, and has for its object to provide an improved lifting skid for use in connection with saw mill feed mechanism for raising a log, cant or board from the cooperating feed rollers and moving the same laterally off from said rollers.

To the above ends the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

The invention is illustrated inthe accom panying drawings, wherein like characters indicate like parts throughout the several views.

Referring to the drawings, Figure 1 is a lan view, with some parts broken away, illustrating my improved lifting skid, socalled, applied in working position with respect to a series of feed rollers. Fig. 2 is a transverse vertical section taken on the line :v2 m2 of Fig. 1, and Fig. 3 is a detail in side elevation, showing the novel manner of pivotally connecting one of the skid beams to its supporting bracket.

The numeral 1 indicates feed rollers, the shafts of which are journaled in suitable bearings 2 on a supporting frame 3, and are connected by miter gears 4-5 to a common drivin shaft 6, which shaft is mounted in suitab e bearings 7 secured on one of the side beams of the framework 3. This shaft 6 may be driven in the usual or any suitable way (not shown) and through the miter gears the several rollers 1 will be rotated in a common direction so that they are adapted to feed a log endwise.

The so-called lifting-skid is made up of a pair of heavy skid bars 8, preferably in the form of castings, and having in their upper faces chain guiding grooves 9. At their right hand ends, as shown in Figs. 1 and 2, these cast skid bars 8 are bifurcated or formed with downwardly curved rongs 8a that are pivotally connected by olts or studs 10 to the Specification of Letters Patent.

Patented May 12, 1908.

Serial No. 389,678.

prongs of a supporting bracket 11, which bracket is bolted or otherwise rigidly secured to the adjacent frame beam 3. These pivot bolts 10, it will be noted, are located eccentric to and outward of the driving shafts 6. This feature is important because it permits the application and removal of the skid bar without interference with the shaft, and, furthermore, makes the pivotal support entirely independent of the shaft journal. The driving shaft 6 is provided withv a pair of driving sprockets l2 that are located one between the prongs 8i1L of each of the skid bars 8. vAt their free ends, the skid bars 8 are also bifurcated to afford clearance for idle sprockets 13 which are journaled to the prongs thereof by short shafts or pins 14. Heavy sprocket chains 15 run. over the alined sprockets 12 and 13 and their upper or working portions run within the grooves 9 of the skid bars 8, but project above the skid bars, so that they are operative to support and carry a log or cant laterally when the skid bars 8 are raised above the upper surface of the rollers 1.

Mounted in suitable bearings 16 secured to the adjacent frame beam 3 below the rollers 1 and below the free ends of the skid bars 8, is a rock shaft 17 which is provided with a air of relatively short arms 18 connected by links 19 to the skid bars 8 near the free ends of the latter. The rock shaft 17 is also provided with an arm 20 which is connected by a link 21 to the piston stern 22 of a reciprocating engine, the cylinder 23 of which is rigidly supported by a suitable framework or other means (not shown). This reciprocating engine is adapted to be operated in the usual way and, as shown, the stem 24 of its distribution valve is yieldingly pressed upward by a spring 25 and is provided with an operating rod 26 that usually extends above the floor of the structure in which the apparatus is installed, and is provided with a foot piece, not shown, which when steppedl upon forces the distribution valve against the tension ofthe spring 25 into its other extreme osition. The arrangement should be such t at when the spring 25 is permitted to operate, the distribution valve of the engine will be held in a position to cause the iston of the engine, and hence the skid bars 8, to be held in their lowered positions. The lowered position of the skid bars 8 (see Fig.

2) is the normal or inoperative position of thev so-called lifting skid.

When the valve stem 24 is forced downward, the piston of the engine will be forced upward in the usual way and through the connections described the skid bars 8 will be raised above the upper surface of the rollers l, and the upper portions of their chains 15 willthen be rendered o erative to lift the 10g or cant from the feed ro 1ers andfeed the same laterally off from said rollers.

Hitherto it has been customary to pivot the skid 'barseither on the driving shaft 6 or on bearingsl concentric therewith. This construction is objectionable because it throws the weight of the load on the shaft ournals, thereby straining the same and frequently throwing the same out of true alinement and, furthermore, because it makes the application and removal of the skid bars from their pivotal supports a difficult matter. As is evident, these objectionable features are overcome in my present invention by providing pivotal su ports for the skid bars that are indepenc ent of the shaft and its journals and are located. eccentric thereto.

What I claim isr' i 1,. ln a mechanism of the kind described, the combination with feed rollers adapted to feed a log or cant endwise, of a driving shaft extending transversely of saidl feed rollers and geared to the shafts thereof, of a lifting skid com rising skid bars extending transversely o said driving shaft and pivotally supported at one end by bearings that are located eccentric to and are independent of said driving shaft and its journals, drivin s rockets carried by said driving shaft an a ined with the pivoted ends of said skid bars, idle sprockets at the free ends of said skid bars, sprocket chains running over said skid bars and the alined sprockets, 4and means for raising and lowering the free ends of said skid bars, substantially as described, 2. ln a mechanism of the kind described,

the combination with feed rollers adapted to feed a log or cant endwise, of a driving shaft extending transversely of said rollers and geared to the shafts thereof, driving sprockets onsaid driving shaft, fixed bifurcated bearing 'brackets having rongs'embracing the outer portions of sai( sprockets, skid bars having bifurcated ends embracing the said sprockets and pivotally attached to the prongs of said bearing bracket at lpoints eccentric to and outward of said driving shaft, idle sprockets journaled in the free ends of said skid bars, chains ruiming over said skid bars and over the alined sprockets, and means for raising and lowering the free ends of said skid bars, to render the chains thereof operative, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

HERMANN DITTBENNER.

Witnesses:

H. D. KILGORE, F D. MERCHANT. 

